Impact of wildfire on the Spotted-tailed Quoll in Kosciuszko National Park

A population of Spotted-tailed Quolls Dasyurus maculatus was studied for three years (2002-2004) in the lower catchment of the Jacobs River, in the Byadbo Wilderness Area of southern Kosciuszko National Park. Survey and monitoring of quoll latrine sites and prey populations, dietary analysis and live-trapping was carried out for one year before and two years after the widespread wildfires of January 2003, which had a very high impact on the study area.

Survey for Spotted-tailed Quoll latrine sites was successful in locating a total of 90 such sites throughout all parts of the topography among large, complex granite outcrops and along rocky sections of riparian habitat. After the fire in 2003, lower numbers of latrines were in use than observed before the fire, and there was a lower level of usage (number of scats) of individual latrines. Continued monitoring in 2004 revealed that many latrines that had become inactive in 2003 following the fire were re-activated in the second breeding season following fire.

Twenty-two different species of mammal were recorded in the diet, representing the majority of all prey identified and contributing almost all of the biomass. Medium-sized mammals were the most important prey category, followed by small mammals, large mammals (most likely taken as carrion) and non-mammalian prey (birds, reptiles, insects and plants). Brushtail Possums were the most important single prey item in all years.

There was a shift in utilisation of food resources by quolls in response to changes in prey availability resulting from the fire. There was a significant decrease in occurrence of Brushtail Possum in scats after the fire and significantly more scats contained hair of lagomorphs (rabbits and hares). Other fire-induced changes to the diet included a significant drop in the occurrence of small mammals in scats, and a peak in occurrence of large mammals in the winter directly following the fire.

A large, high-density population of quolls was live-trapped and marked during the winter breeding season of 2002. Trapping over the 2003 and 2004 winter breeding seasons revealed that the high-intensity wildfire did not result in the extinction of the local population. There was evidence of a small, short-term decline in the number of quolls in the study area in the 2003 breeding season with a notably reduced male population outnumbered two-to-one by females. Trapping in 2004 showed a recovery of the population to numbers exceeding that observed prior to the fire, although there was some evidence that recruitment of young from the post-fire breeding season in 2003 was reduced because of the fire.

Publications/References

Dawson, J.P. (2005). Impact of wildfire on the spotted-tailed quoll Dasyurus maculatus in Kosciuszko National Park. MSc Thesis. University of New South Wales, ADFA, Canberra.